How DataGrid is notified when item in the collection is changed?

Question

I have two DataGrids bound to the same ObservableCollection property in my ViewModel. When I edit an existing row in one DataGrid another gets updated after row is commited.

But how it works? The NotifyCollectionChanged event is not raised on the underlying ObservableCollection. I have checked it by subscribing to the event.

Answer 1

In this case, you are modifying the properties of the item (entity) of the collection, not the collection itself.
Therefore, the CollectionChanged event is not raised.
To update properties in an entity, INotifyPropertyChanged must be implemented in it.
But if the change of properties happens ONLY through bindings, then even this is not necessary.
Bindings use PropertyDescriptor and other types of reflection in their work.
This allows bindings to "know" that a property has been changed by another binding.

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